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Page s0 Thinking Questions 1. As a field researcher you are sent to the Arizona

ID: 275070 • Letter: P

Question

Page s0 Thinking Questions 1. As a field researcher you are sent to the Arizona desert to study the prairie dog species C. ludiv determine if the population is in Hardy-Weinberg equilibrium. Specifically you are studying this population with respect to the gene that determines the coat color in C: ludivincianus. This trait is coded for by a single gene (the NDY6 gene) with two alleles (N, n) and is passed down from one generation to the next. After sampling 170 of these prairie dogs, you find that 36% of the C. ludivíncianus population is homozygous recessive for coat color. Assuming that the population is in Hardy-Weinberg equilibrium... a. What is the alele frequency of the N allele? b. What is the frequency of homozygous dominant prairie dogs? c. What is the frequency of heterozygous prairie dogs? d. What conditions must be being satisfied? Sixty flowering plants are planted in a flowerbed. Forty of the plants are red-flowering homo dominant Twenty of the plants and reseed themselves for several years. In a subsequent year, 178 red-flowered plants, 190 pink-flowered 2. are white-flowering homozygous recessive. The plants naturally and 52 white-flowered plants are found in the flowerbed. Use a ch-square analysis to determine if

Explanation / Answer

1. Hardy-Weinberg equilibrium:

p+q = 1

p2+2pq+q2 = 1

Required conditions:

The population must be large

There is no emigration or immigration

Sexual reproduction is random

No selection

No mutations

Total population = 170

Since it is a diploid organism, total number of alleles = 170 X 2 =340

Frequency of nn, q2 = 36% = 0.36

Frequency of n allele, q = 0.6

Frequency of N allele, p = 1 - 0.6 = 0.4

Frequency of NN, p2 = 0.4 X 0.4 = 0.16

Frequency of Nn, 2pq = 2 X 0.6 X 0.4 = 0.48